There are a couple of ways to color wash concrete, depending on the look you want. Color washing concrete can give your patio or driveway a clean, new look. You do not need a lot of paint for this procedure and you can can use patio paints that are readily available at your local craft or home improvement store.
Decide which effect you want. You can use patio paints or an iron oxide wash. Iron oxide washes give a more rustic look to the cement. Thinner paint solutions give a crisper look. Purchase the paint you want based on the look you desire.
Seal the concrete or tile with one or more coats of sealer. This will help you control the coloring. For an antique or used brick look, dilute a white water-based paint with water, then add color. Add as much or as little as you need for the desired shade. Apply the mixture between coats of sealer.
Squeeze 2 to 3 tablespoons of patio paint into a plastic container. Mix it with enough water to create a smooth mixture. Brush the color over the surface of the stone, making sure to get it into all the nooks and crannies of the design.
Use a rag or towel moistened with warm water to wipe the top of the design surface clean of paint. Leave the paint in the lower crevices of the design. This will give a concrete surface with a 3-D design color in the background, while the plain cement stands out on top.
Mix iron oxide (it comes in various colors) with water into a thin, soupy-like mixture. Apply to uncured castings once you have removed the molds.
Brush the wash onto the entire surface, making sure to get it into any nooks and crannies. Wipe the top of the surface with a moist towel or rag until the color is light enough for your tastes. You will end up with a darker color in the background and a lighter color on the top of the design.